Regarding French salaries again : yes they are lower than elsewhere but with some exceptions, French employers are not the problem : they do pay the same price for you as in other European countries, more or less ! The difference is that your average engineer in France costs them around 1.5-2.5 times the total take home pay, because of high, compulsory labor taxes.
In exchange, employees get as standard :
* a top notch, virtually free healthcare system with no concept of exclusions or "pre-conditions"
* Usually no student loans to repay because their higher education was free, unless they went for a private business/engineering school but that's still an order of magnitude cheaper than a US university.
* a comfortable (unsustainable ?) state pension later on.
* unemployment insurance that covers around 70% pay for months.
* 5 weeks holiday + public holidays
* Non San Francisco / London / NYC renting costs (although Paris is quite bad by French standards, and much worse than Berlin)
If you're US-based, think about your monthly budget and what goes towards healthcare/co-pay, student loans, kids college fund, 401k, and building an emergency fund in case you get laid off / severely ill. None of that is strictly required in France (although some of it is available as extra private coverage, and a good idea)
This is why cross-border salary comparisons are pointless, it's really apples & oranges.
I'm French and living in London, and I'd personally rather have the freedom to have a higher take-home pay and contribute towards the above items myself as I see fit. But I'm not fooling myself thinking that because my take-home pay is twice as high each month, the math is as simple as that. I know that I'm so much more on my own here than at home...